Develop Reference

how to decrypt sqlite database android using sqlcipher?

I need a local database for my application.I created one and i encrypted it.(I know the pw).Now i want to load this db to my original application's assets folder.I want to decrypt it before copy.
I had a copy code like this this is working for unencrpyted db.
How can I translate this for my encrypted db.Thanks
private void copyDataBase() throws IOException {
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[5120];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}

The proper way to do this would be to copy the encrypted database into a local folder. Then you can open it with SQLCipher and use sqlcipher_export() to convert it into a standard (non-encrypted) SQLite database.

Android SQLite database re-Import

in my project i have imported a sqlite database using this..
private void copyDataBase() throws IOException{
InputStream myInput = myContext.getAssets().open(DB_NAME);
String outFileName = DB_PATH + DB_NAME;
OutputStream myOutput = new FileOutputStream(outFileName);
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
myOutput.flush();
myOutput.close();
myInput.close();
}
It Works fine. But When I delete the database file from the DDMS File Explorer and try to import it again, the code breaks down.
it says no such file found and create a empty database...
Is there any way to overcome this problem?

You Have to delete the previous database before import it again.
use this Context.deleteDatabase("DB_NAME")

Copy two SQLite Database in asset folder in Android

For the last few days I've been trying to copy two databases in the asset folder, but could not get any success.
One database I managed to copy and access it. But the second one, I need your help.

private void copydatabase() throws IOException {
//Open your local db as the input stream
InputStream myinput = mycontext.getAssets().open(DB_NAME);// Path to the just created empty db
String outfilename = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myoutput = new FileOutputStream("/data/data/(packagename)/databases /(datbasename).sqlite");
// transfer byte to inputfile to outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myinput.read(buffer))>0)
{
myoutput.write(buffer,0,length);
}
//Close the streams
myoutput.flush();
myoutput.close();
myinput.close();
}
Do this for your second database.

No such table on HTC desire HD (SQLite database on Android)

Please take a look at the following function :
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
File f = new File(DB_PATH);
if (!f.exists()) {
f.mkdir();
}
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
//myInput.read(buffer);
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
Where DB_PATH is "/data/data/application package/databases/". Is it possible to set DB_PATH="" ? Actually setting DB_PATH = "/data/data/application package/databases/". works fine on most devices, but does not work on HTC desire HD ( discussed here , here , here and here ). This device does not find the mentioned path on the device.
Thanks

You should set your DB_PATH like this:
String DB_PATH = context.getDatabasePath(DB_NAME).getAbsolutePath()
That will give you the full path to your Database.. then you can use that as your outFileName.

Android prefilled DB

Is it possible to supply prefilled SQLite DB to my app? I want to use db as ordinary SQLite db which will have tables filled manually and I want to include it into my .apk file.

Yes, include it in your assets folder and copy it into the /databases folder when your application first launches.

try this
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}

Including in the assets folder is one option (Apk size will be increased.)
How about storing the pre-filled db on any cloud storage service provider and downloading the file on the first run of the app?